Process for breaking petroleum emulsions employing certain oxyalkylated dipentaerythritols



Jan. 7, 1958 DE GRQQTE ETAL 2,819,215

PROCESS FOR BREAKING PETROLEUM EMULSIONS EMPLOYING CERTAIN OXYALKYLATED DIPENTAERYTHRITOLS Filed May 24, 1954' BUTYLENE OXIDE iOO 9 0 l2 G H .3 l4 l 0 B H o I DIPENTAERYTHRITOL. ETHYLENE I00 /0 OXIDE |OO% IN V EN TORS PROCESS FOR BRE G PETROLEUM EMUL- SIONS EMPLOYENG CERTAIN OXYALKYLATED DIPENTAERYTIHQHOLS Melvin De Groote, University City, and Owen H. Pettingill, Kirkwood, Mo., assignors to Petrolite Corporation,

Wilmington, Del, a corporation of Delaware Application May 24, 1954, Serial No. 431,783 2t) Claims. (Cl. 252-331) This invention relates to processes or procedures particularly adapted for preventing, breaking or resolving emulsions of the water-in-oil type, and particularly petroleum emulsions.

Our invention provides an economical and rapid process for resolving petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring Waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

It also provides an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or Weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned are of significant value in removing impurities particularly inorganic salts, from pipeline oil.

More specifically then, the present invention is concerned with a process for breaking petroleum emulsions employing a demulsifier including a cogeneric mixture of a homologous series of glycol ethers of dipentaerythritol. The cogeneric mixture is derived exclusivelyfrom dipentaerythritol, ethylene oxide and butylene oxide in such weight proportions so the average composition of said cogeneric mixture stated in terms of initial reactants lies approximately within the 5-sided figure of the accompanying drawing in which the minimum dipentaerythritol content is at least 1.5% and which 5-sided figure is identified by the fact that its area lies within the straight lines connecting A, B, C, D, and H.

We have found that when dipentaeiythritol is combined with butylene oxide and ethylene oxide in certain proportions' and particularly when the butylene oxide is employed first, followed by use of ethylene oxide and more especially if the butylene oxide employed is one of the straight chain isomers.

or a mixture of the two and if the composition falls Within surface activity is a factor, either directly or indirectly.

One example is the use of such derivatives in the resolution of petroleum emulsions of the Water-in-o'il type.

In a general way the compounds which have beenfound most eifective and fall within the limits of the chart are combinations where one part of dipentaery-thritol has been treated with about 11 to'39 parts of butylene oxide, by weight, and then reacted with 27 to 58.5 parts of ethylene oxide.

In another series parts of dipentaerythritol have been reacted with 5 parts by weight of butylene oxide and 85 parts by weight of ethylene oxide. In another series 1.5

parts by weight of dipentaerythritol have been reacted with 13.5 parts by weight of butylene oxide and 85 parts by 2,819,216 issue is 958.

weight of ethylene oxide.v Similarly, in another series the following combinations have been used: 1.5 parts of dipentaerythritol combined with 58.5 parts by weight of butylene oxide and 40 parts by weight of ethylene oxide; 20 parts by weight of dipentaerythritol, reacted with 40 parts by weight of butylene oxide and then with 40 parts by weight of ethylene oxide. In another series 20 parts by weight of dipentaerythritol were reacted with 10 parts by weight of butylene oxide and then 70 parts by weight of ethylene oxide.

It is of interest to note in some instances as little as 1.5 parts of dipentaerythritol may be combined with 98.5 parts of the two oxides to produce very valuable derivatives.

We have also found that where part of the butylene oxide is replaced by propylene oxide, i. e., where a com bination of dipentaerythritol, butylene oxide, propylene oxide and ethylene oxide are used, effective and valuable surface-active agents can also be obtained. This, however, represents a separate invention.

For the purpose of resolving petroleum emulsions of the water-in-oil type, we prefer to employ oxyalkylated derivatives, which are obtained by the use of monoepoxides, in such manner that the derivatives so obtained have sufiicient hydrophile character to meet at least the test set forth in U. S. Patent No. 2,499,368, dated Mar-ch 7, 1950, to De Groote and Keiser. In said patent such test for emulsification using a water-insoluble solvent, generally xylene, is described as an index of surface activity.

The above mentioned test, i. e., a conventional emulsification test, simply means that the preferred product for demulsification is soluble in a solvent having hydrophobeproperties or in an oxygenated water insoluble or even a fraction of a water-soluble hydrocarbon solvent and that when shaken with Water the product may remain in the nonaqueous solvent or, for that matter it may pass into the aqueous solvent. In other Words, although it is xylene soluble, for example, it may also be water soluble to an equal or greater degree.

For purpose of convenience what is said hereinafter will be divided into three parts:

. Part 1 is concerned with the oxyalkylation of dipentaerythritol in general;

Part 2 is concerned with the oxyalkylation of dipentaerythritol using two difierent oxides, i. e., butylene oxide and ethylene oxide so as to produce derivatives falling Within certain composition limitations hereinafter noted in detail. For convenience, Part 2 is divided into two sections, Section A is concerned with oxybutylation and oxyethylation broadly, and Section B is concerned with the particular compositions corresponding to the herein specified compositions and illustrate such combinations;

Part 3 is concerned with the resolution of petroleum emulsions of the water-in-oil type by means of the previously described chemical compounds.

PART 1 At the present time there is available butylene oxide which includes isomeric mixtures, for instance, one manufacturer has previously supplied a mixed butylene oxide which is in essence a mixture of l-butene oxide, 2-

' butene oxide isomers and approximately 10% isobutylene oxide. Another manufacturer has supplied an oxide which is roughly a fifty-fifty mixture of the cisand trans-isomers of 2-butene oxide. 7 I

There is also'a'vail'able a butylene oxide which'is characterized as straight chain isomers being a mixture of the 1,2 and the 2,3 isomers and substantially free from the isobutylene oxide.

This latter product appears to consist of of the 1,2 isomer and 15% of the mixed 2,3 cisand 2,3 transisomer. We have obtained the best results by using an oxide that is roughly 80% or more of the 1,2 isomer and with either none, or just a few percent if any, of the isobutylene oxide, the difference being either form of the 2,3 or a mixture of the two forms.

Our preference is to use an oxide substantially free from the isobutylene oxide, or at least having minimum amounts of isobutylene oxide present.

Since the varying solubility of different butanols is well known, it is unnecessary to comment on the efliect that the varying structure has on solubility of derivatives obtained by butylene oxide. Purely by way of example, the applicants have tested the solubility of the first two available butylene oxides and noted in one instance the butylene oxide would dissolve to the extent of 23 grams in 100 gramsof water, whereas the other butylene oxide would only dissolve to the extent of 6 grams in 100 grams of water. These tests were made at 25 C.

As to further reference in regard to the isomeric butylene oxides see Chemistry of Carbon Compounds, volume I, part A, Aliphatic Compounds, edited by E. H. Rodd, Elsevier Publishing Company, New York, 1951, page 671'.

As to the diiference in certain proportions of the cisand trans-form of straight chain isomers 2,3-epoxybutane see page 341 of A Manual of Organic Chemistry, volume 7,. G. Malcolm Dyson, Longmans, Green and Company, New York, 1950.

Reference to butylene oxide herein of course is to the compound or compounds having the oxirane ring and thus excludes 1,4-butylene oxide (tetrahydrofurane) or a trimethylene ring. compound.

When reference is made to the oxides, for instance, ethylene oxide and butylene oxide, one canuse the corresponding carbonates. Ethylene carbonate is available commercially. Butylene carbonate, or the carbonate corresponding. to a particular oxide, is not available commercially but can be prepared by the usual methods in the laboratory. For this reason further reference to the alkylene carbonates will be ignored although it is understood when oxyethylation takes place by means of ethylene carbonate one could, of course, use butylene carbonate for oxybutylation.

In the present invention we have foundthat outstanding products are obtained by the use of certain preferred butylene oxides, i. e. those entirely free or substantially free (usually 1% or less) and composed of approxirnately 85% or more of the 1,2 isomer with the remainder, if any, being the 2,3 isomer.

In the preparation of the outstanding compounds We have studiously avoidedthe presence of the isobutylene oxide as far as practical. When any significant amount of isohutylene oxide happens to be present, the results are not as satisfactory regardless of the pointwhen the butylene oxide is introduced. One explanation may he the following. The initial oxybutylation which may be simplified by reference to amonohydric alcohol, produces a tertiary alcohol. Thus the oxybutylation in the presence of an alkaline catalyst may be shown thus:

lic chloride such as ferric chloride, stannic chloride, aluminum chloride, etc.

The difliculty is that there may be some tendency on the part of dipentaerythritol to polymerize further, i. e., to form tripentaerythritol or the like. If this does happen to occur oxyalkylation would then involve dipentaerythritol plus tripentaerythritol or even a higher polymer, and water in part. We have tried procedures such as using an alkaline catalyst and dipentaerythritol employing 4 to 6 moles of isobutylene oxide per mole of dipentacrythritol. Afterwards an amount of acid was added equal to the amount of caustic used as a catalyst and the reaction mass dried and then stannic chloride added. Under such circumstances the results suggest more satisfactory oxybutylation as such although the procedure becomes cumbersome, uneconomical and perhaps even impractical.

This, however, seems to be only a partial explanation. Another explanation may rest with the fact that isobutylene oxide may show a tendency to revert back to isobutylene and oxygen and this oxygen may tend to oxidize the terminal hydroxyl radicals. This possibility is purely a matter of speculation, but may account for the reason we obtain much better results using a butylene oxide as specified. In regard to this reaction, i. e., possible conversion of an alkylene oxide back to the olefine and nascent oxygen, see Tall oil studies: II. Decolorization of polyethenoxy tallates with ozone and hydrogen peroxide, J. V. Karabinos et 211., I. Am. Oil Chem. Soc. 31, 71 (1954).

In order to illustrate why the herein contemplated compounds or said products are cogeneric mixtures and not single chemical compounds, and why they must be described in terms of manufacture, and molal ratio or percentage ratio of reactants, reference is made to a monohydric alcohol. Dipentaerythritol, of course, is a polyhydric alcohol having 6 hydroxyls. However, one need only consider What happens when a monohydric alcohol is subjected to oxyalkylation.

If one selects any hydroxylated compound and subjects such compound to oxyalkylation, such as oxyethylation, it becomes obvious that one is really producing a polymer of the alkylene oxide except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units: If such a compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide it is well known that one does not obtain a single constituent which, for sake of convenience, may be indicated as RO(C H O') H. Instead, one obtains a cogeneric mixture of closely related homologues in which the formula may be shown as the following: RO(-C H O),,H, wherein n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25 and perhaps less, to a point Where 12 may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental principles of condensation polymerization, by Paul J. Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of. touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difiiculty, it is necessary to resortto some other'meth- 0d of description.

What has been said in regard to a monohydric' compound of course is multiplied many times in the case of ahexahydric compound such as dipentaerythritol. This is particularly true even in regard to ethylene oxide alone but becomes even more complicated when butylene oxide is used in light of what has been said previously in regard to the isomers of butylene oxide.

PART 2 Section A We have found that we can oxybutylate dipentaerythritol in the same manner that it is conventionally oxypropylated. For example, we have followed the directions which appear in columns 11 and 12 of U. S. Patent No. 2,626,907 dated January 27, 1953, to De Groote, in regard to the oxypropylation of dipentaerythritol and substituting butylene oxide for propylene oxide and continuing the operation in identically the same way. We completed the reaction with the same conditions set forth in Examples 1a through 5a, inclusive. Stirrer speed, temperature, time period, amount of solvent used, amount of catalyst used, and operating pressure were substantially the same.

Numerous other patents include specific information as to the oxypr-opylation of pentaerythritol and pentaerythritol polymers. Actually the procedure is substantially the same whether one uses butylene oxide, propylene oxide or ethylene oxide.

It is not believed any examples are necessary to illustrate such well known procedure but for purpose of illustration the following are included.

Example 1a The reaction vessel employed was a stainless steel autoclave with the usual devices for heating, heat control, stirrer, inlet, outlet, etc., which is conventional in this type of apparatus. The capacity was approximately 4 liters. The stirrer operated at a speed of approximately 250 R. P. M. There were charged into the autoclave 500 grames of dipentaerythritol, 300 grams of xylene, and 15 grams of sodium methylate. The autoclave was sealed, swept with nitrogen gas and stirring started immediately and heat applied. The temperature was allowed to rise to approximately 148 C. At this particular time the addition of butylene oxide was started. The butylene oxide employed was a mixture of the straight chain insomer substantially free from isobutylene oxide. It was added continuously at such speed that it was absorbed by the reaction as added. The amount added in this operation was 1500 grams. The time required to add the butylene oxide was two hours. During this period the temperature was maintained at 130 to 148 C. using cooling water through the inner coils when necessary and otherwise applying heat it required. The maximum pressure during the reaction was 55 pounds per square inch. Ignoring the xylene and sodium methylate and considering the dipentaerythritol for convenience, the resultant product represents 3 parts by weight of butylene oxide to one part by weight of dipentaerythritol. The xylene present represented approximately .6 of one part by Weight.

Example 2a Example 312 In a third step, instead or" adding 1500 grams of butylene oxide, 1625 grams were added. The reaction slowed up and required approximately 6% hours, using the same operating temperatures and pressures. The ratio at the end of the third step was 9.25 parts by weight of butylene oxide per weight of dipentaerythritol.

Example 4a At the end of this step the autoclave was opened and an additional 5 grams of sodium methylate added, the autoclave flushed out as before, and the fourth and final oxyalkylation completed, using 1625 grams of butylene oxide, and the oxyalkylation was complete within 4 /2 hours using the same temperature range and pressure as previously. At the end of the reaction the product represented approximately 12.5 parts of butylene oxide by weight to one part of dipentaerythritol.

All the examples, except the first step, were substantially water-insoluble and xylenesoluble.

As has been pointed out previously these oxybutylated dipentaerythritols were subjected to oxyethylation in the same manner described in respect to the oxypropylated dipentaerythritol in aforementioned U. S. Patent No. 2,626,907. Indeed, the procedure is comparatively simple for the reason that one is working with a liquid and also that ethylene oxide is more reactive than butylene oxide. As a result, using the same amount of catalyst one can oxyethylate more rapidly than usually at a lower pressure. There is no substantial difference as far as operating procedure goes whether one is oxyethylating oxypropylated dipentraerythritol or oxybutylated dipentraerythritol.

The same procedure using a slurry of finely powdered dipentaerythritol in xylene was employed in connection with ethylene oxide and the same mixture on a percentage basis Was obtained as in the above examples where butylene oxide and dipentaerythritol were used.

The same procedures have been employed using other butylene oxides including mixtures having considerable isobutylene oxide and mixtures of the straight chain isomers with greater or lesser amounts of the 2,3 isomer.

Where reference has been made in previous examples to the straight chain isomer, the product used was one which was roughly or more of the 1,2 isomer and approximately 15% of the 2,3-cisand the 2,3-transisomer with substantially none or not over 1% of the isobutylene oxide.

In the preceding procedures one oxide has been added and then the other. One need not follow this procedure. The two oxides can be mixed together in suitable proportions and subsequently subjected to joint oxyalkylation so as to obtain products coming Within the specified limits. In such instances, of course, the oxyalkylation may be described as random oxyalkylation insofar that one cannot determine the exact location of the butylene oxide or ethylene oxide groups. In such instances the procedure again is identically the same as previously described and, as a matter of fact, we have used such methods in connection with molten sorbitol.

If desired, one may add part of one oxide and all of the other and then return to the use of the first oxide, for instance; or one may use the procedure as previously, adding first some butylene oxide, then ethylene oxide and then the butylene oxide. Or, inversely, one may add some ethylene oxide, then all butylene oxide and then the remainder of the ethylene oxide; or either oxide could be added in portions so that first one oxide is added, then the other, then the first oxide is added again, and then the second oxide. We have found no advantage in so doing. Indeed, our preference has been to add all the butylene oxide first and then the required amount of ethylene oxide.

As pointed out previously, dipentaerythritol' can be oxyethylated in the same way it is oxybutylated, i. e., by preparing a slurry in xylene or in a similar solvent and using a suitable alkaline catalyst such as caustic soda, sodium methylate, or the like, and then adding the ethylene oxide. The changes previously mentioned are of difference in degree only. In other Words, oxyethylation will take place at a lower temperature, for instance, a top temperature of probably to C. instead of to 7 150 C. The same weight of ethylene oxide could be added in 75% to 85% of the time required for butylene oxide. The pressure during the reaction, instead of being 35 to 45 pounds as in the case of butylene oxide, is apt to be to pounds and at times a little higher. Otherwise, there is no difference.

Also,if desired, the use of ethylene carbonate is a very convenient way of oxyethylating dipentaerythritol. In fact, it can be oxyethylated without the use of pressure. Such procedure, and particularly melting the carbonate first and adding the powdered dipentaerythritol slowly permits the production of a reaction mass which is a liquid or which melts readily at comparatively low temperatures to yield a liquid. Such reaction should be conducted in such a way that there is no residual ethylene carbonate when the mass is transferred to an autocalve.

One can oxyalkylate using an acid catalyst or an alkaline catalyst or at least in part, without the use of any catalyst although such procedure is extremely slow and uneconomical. In other words, any one of the conventional catalysts used in oxyalkylation may be employed. It is our preference, however, to use an alkaline catalyst such as sodium methylate, caustic soda, or the like.

Actually, finely powdered dipentaerythritcl may contain a trace of moisture. Our preference is to prepare the slurry with an excess of xylene and distill otf a part of the xylene so as to remove any trace of water and then flush out the mass with nitrogen. Even so, there may be a few tenths of a percent of moisture remain although at times examination indicates at the most it is merely a trace.

Section B In light of what has been said previously, particularly in Section A, it is obvious that hardly any directions are required to produce the compounds herein specified. However, referring to the composition of the initial reactants based on the S-sided figure in the attached drawing, it

TABLE I Tertiary mixture, Binary intermediate mixtures,

percent basis percent basis Points on boundary of area Dipen- Butyl- Ethyl- Dipen- Butyl- Dlpen- Ethyltaerythone one taerythene tacrythenc ritol oxide oxide ritol oxide ritol oxide 10.0 5.0 85.0 66. 6 33. 4 10. 5 89. 5 1. 5 18. 5 85. 0 10. 0 90. 0 1. 7 98. 3 l. 5 58. 5 40. O 2. 5 97. 5 3. 6 9G. 4 20. 0 40. 0 40. 0 33. 4 U6. 6 33. 1 66. (l 1. 5 40. 0 58. 5 3. 6 96. 4 2v 5 97. 5 1. 5 30.0 68. 5 4. 75 95. 2.14 97. 8G 1. 5 20.0 78. 5 7.0 93. 0 1. 87 98.13 20. 0 10.0 70. 0 66. 6 33. 4 22. 2 77. 8 20.0 20.0 60. 0 50.0 50.0 25.0 75.0 20. 0 30.0 50. 0 40. 0 60. O 28. 6 71. 4 5.0 52. 5 42. 5 8. 68 91. 32 10.5 89. 5 8. 0 44. O 48. 0 15. 4 84. 5 14. 3 85. 7 1. 5 54. 5 44. 0 2. (38 97. 32 3. 3 7 18.0 36. 5 15. 5 33. 0 67. 0 28. 3 71. 7 15. 0 33. 5 51. 5 31. 0 (39. 0 22. 6 77. 4 7. 5 3G. 5 56. 0 17. l 82. 9 11. 8 88. 2 1. 5 34. 5 64. 0 4. 16 95. 84 2. 3 97. 7 17.0 28.0 55.0 37.7 62. 3 23. 6 76. 4 7.0 26. 0 67. 0 21. 2 78. 8 9. 5 90.5 13. 5 22. 5 64. 0 37. 5 62. 5 17. 4 82. 6 15. 5 19. 0 G5. 5 44. 8 55.2 19. 2 80. S

:positions shown on the chart.

Note the firstcolumn-gives the .particular point'on the boundary ofthe S-sided figure or within the S-sided figure area. Note the next three columns representthe tertiary mixture which corresponds to the initial reactants, to wit, the percentages, by weight, of dipentaerythritol, butylene oxide and ethylene oxide. Thus it is apparent that one could select any particular point and simply use the appropriate number of pounds of oxide; for instance, in regard to point A all that would be necessary would be to mix 5 pounds of butylene oxide with pounds of ethylene oxide and use the mixture to oxyalkylate 10 pounds of dipentaerythritol.

Similarly, in Example B, one need only mix 13.5 pounds of butylene oxide with 85 pounds of-ethylene oxide and use the mixture to oxyalkylate 1.5 pounds of dipentaerythritol in the manner previously indicated.

Note the fifth and sixth columns represent binary intermediate mixtures. For instance, in .regard to the various points on the boundary and within the S-sided figure area, we have calculated the initial mixture using dipentaerythritol and butylene oxide in the first case, and using depentaerythritol and ethylene oxide in the second case, which would -be employed for subsequent oxyalkylation to give the particular composition required. Note that a binary intermediate for the preparation of point A can be prepared in any suitable manner involving 66.6% of dipe'ntaerythritol and 33.4% of butylene oxide. Thus, for example one could use 66.6 pounds of dipentaerythritol and 33.4 pounds of butylene oxide, or on a larger scale one could use 666 pounds of dipentaerythritol and 334 pounds of butylene oxide.

Referring now 'to the tertiary mixture table, it is apparent that for point A dipentaerythritol and butylene oxide together represent 15% and ethylene oxide 85%. Therefore, one could employ 15 pounds of the binary mixture and react it with 85 pounds of ethylene oxide.

Similarly, in regard to the fifth and sixth columns for point B, the initial mixture involved dipentaerythritol and butylene oxide, representing 10% of dipentaerythritol and of butylene oxide. If desired, 10 pounds of dipentaerythritol could be reacted with 90 pounds of butylene oxide. Such mixture need only be reacted with ethylene oxide by reacting 15 pounds of the mixture with 85 pounds of ethylene oxide. This is obvious from the data in regard to the tertiary mixtures.

Referring now to columns 7 and 8, it is obvious one could readily produce an oxyethylated dipentaerythritol and then subject it to reaction with butylene oxide. Using this procedure in regard to A, it is obvious that the mixture represents 10.5% of dipentaerythritol and 89.5% of ethylene oxide. This product could be obtained from a binary mixture of 105 pounds of dipentaerythritol and 895 pounds of ethylene oxide.

Referring now to the tertiary mixture table, it is obvious that pounds of such mixture could be reacted with 5 pounds of butylene oxide to give point A. Similarly, in regard to point B the oxyethylated dipentaerythritol represents 1.7% of dipentaerythritol and 98.3% ethylene oxide. The mixture so obtained by referring to the tertiary mixture table would be reacted with butylene oxide in the proportion of 86.5 pounds of the mixture and 13.5 pounds of butylene oxide.

As previously pointed out, the oxyalkylation of dipentaerythritol has been described in the literature and is described also in detail above. All one need do is employ such conventional oxyalkylation procedure to obtain products corresponding to the compositions as defined. Attention is again directed to the fact that one need not add the entire amount of either oxide at one time but that a small portion of one could be added and then another small portion or" the other, and the process repeated.

Purely for puipose of illustration, we have prepared examples three difierentways corresponding to the com In the first series the butylene oxides and ethylene oxides were mixed; this series is indicated as Aa, Ba, through and including 18a; in the second series butylene oxide was used first followed by ethylene oxide and this series indicated Ab, Eb, through and including 18b; and finally in the third series ethylene oxide was used followed by butylene oxide and the series identified as Ac, Bc, through and including 180.

TABLE II Composition Composition Composition where butylwhere ethyl- Composition corresponding where oxides ene oxide is one oxide is to following point are mixed used first used first prior to oxyfollowed by followed by alkylation ethylene butylene oxide oxide The products obtained by the above procedure usually show some color varying from a light amber to a pale straw. They can be bleached in the usual fashion using bleaching clays, charcoal, or an organic bleach, such as peroxide or peracetic acid, or the like.

Such products also have present a small amount of alkaline catalyst which can be removed by conventional means, or they can be neutralized by adding an equivalent amount of acid, such as hydrochloric acid. For many purposes the slight amount of residual alkalinity is not objectionable.

There are certain variants which can be employed without detracting from the metes and bounds of the invention, but for all practical purposes there is nothing to be gained by such variants and the result is merely increased cost. For instance, any one of the two oxides can be replaced to a minor percentage and usually to a very small degree, by oxide which would introduce substantially the same group along with a side chain, for instance, one could employ glycidyl methyl ether, glycidyl ethyl ether, glycidyl isopropyl ether, glycidyl butyl ether or the like.

In the hereto appended claims reference has been made to glycol ethers of dipentaerythritol. Actually it well may be that the products should be referred to as polyol ethers of dipentaerythritol in order to emphasize the fact that the final products of reaction have more than two hydroxyl radicals. However, the products may be considered as hypothetically derived by reaction of di pentaerythn'tol with the glycols, such as ethylene glycol, butylene glycol, propylene glycol, or polyglycols. For this reason there seems to be a preference to use the terminology glycol ethers of dipentaerythritol.

PART 3 As to the use of conventional demulsifying agents, reference is made to U. S. Patent No. 2,626,929, dated January 7, 1953, to De Groote, and particularly to Part 3. Everything that appears therein applies with equal force and effect to the instant process, noting only that where reference is made to Example 13b in said text beginning in column 15 and ending in column 18, reference should be to Example 18b, herein described.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to a demulsifying agent including a cogeneric mixture of a homologous series of glycol ethers of dipentaerythritol; said cogeneric mixture being derived exclusively from dipentaerythritol, ethylene oxide and butylene oxide in such weight proportions so the average composition of said cogeneric mixture, stated in terms of initial reactants, lies approximately within the 5-sided figure of the accompanying drawing in which the minimum dipentaerythritol content is at least 1.5% and which 5- sided figure is identified by the fact that its area lies within the straight lines connecting A, B, C, D, and H.

2. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst.

3. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first.

4. The process of claim 1 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first, and with the further proviso that the butylene oxide is substantially free from isobutylene oxide.

5. The process of claim 1 with the proviso that oxy alkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first, and with the further proviso that the butylene oxide consists of or more of the 1,2-isomer and approximately 15% or less of the 2,3-isomeric form, and is substantially free from isobutylene oxide.

6. The process of claim 5 with the proviso that the reactant composition falls within the triangular area defined by C, D, and E.

7. The process of claim 5 with the proviso that the reactant composition falls within the parallelogram D, E, F, and J.

8. The process of claim 5 with the proviso that the reactant composition falls within the parallelogram J, F, G, and I.

9. The process of claim 5 with the proviso that the reactant composition falls within the trapezoid I, G, B, and H.

10. The process of claim 5 with the proviso that the reactant composition falls within the triangle H, B, A.

11. A process for breaking petroleum emulsions of the water-in-oil type characterized by subjecting the emulsion to a demulsifying agent including a cogeneric mixture of a homologous series of glycol ethers of dipentaerythritol; said cogeneric mixture being derived exclusively from dipentaerythritol, ethylene oxide and butylene oxide in such weight proportions so the average composition of said cogeneric mixture, stated in terms of initial reactants, lies approximately within the 5-sided figure of the accompanying drawing in which the minimum dipentaerythritol content is at least 1.5 and which 5-sided figure is identified by the fact that its area lies within the straight lines connecting A, B, C, D and H; with the proviso that the hydrophile properties of said cogeneric mixture in an equal weight of xylene are sufiicient to produce an emulsion when said xylene solution is shaken vigorously with one to three volumes of water.

12. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst.

13. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first.

14. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first, and with the further proviso that the butylene oxide is substantially free from isobutylene oxide. 1

15. The process of claim 11 with the proviso that oxyalkylation takes place in presence of an alkaline catalyst and that the butylene oxide be added first, and with the further proviso that the butylene oxide consists of 85% or more of the 1,2-isorner and approximately 15% or less of the 2,3-is0meric form, and is substantially free from isobutylene oxide.

16. The process of claim 15 with the proviso that the reactant composition falls within the triangular area clefined by C, D, and E.

17. The process ofclaim 15 with the proviso that the reactant composition falls within the parallelogram D, E, F, and J. 1 5

18.' The process of claim 15 with the proviso that the reactant composition falls Within the parallelogram I, F, G, and I.

19. The process of claim 15 with the proviso that the: reactant composition falls Within the trapezoid I, G, B,

and -H.

20. The process of claim 15 with the proviso that the reactant composition falls within the triangle H, B, A;

References Cited in the file of this patent UNITED STATES PATENTS 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO A DEMULSIFYING AGENT INCLUDING A COGENERIC MIXTURE OF A HOMOLOGOUS SERIES OF GLYCOL ETHERS OF DIPENTAERYTHRITOL; SAID COGENERIC MIXTURE BVEING DERIVED EXCLUSIVELY FROM DIPENTAERYTHRITOL, ETHYLENE OXIDE AND BUTYLENE OXIDE IN SUCH WIEGHT PROPORTIONS SO THE AVERAGE COMPOSITION OF SAID COGENERIC MIXTURE, STATED IN TERMS OF INITIAL REACTANTS, LIES APPROXIMATELY WITHIN THE 5-SIDED FIGURE OF THE ACCOMPANYING DRAWING IN WHICH THE MINIMUM DIPENTAERYTHRITOL CONTENT IS AT LEAST 1.5% AND WHICH 5THE STRAIGHT LINES CONNECTING A, B, C, D AND H. 